Merge pull request #177 from vpython/attach_arrow

Attach arrow

Author: BruceSherwood

labextension/vpython/src/glowcommlab.js

@@ -479,14 +479,14 @@ var attrsb = {'a':'userzoom', 'b':'userspin', 'c':'range', 'd':'autoscale', 'e':
               'y':'markers', 'z':'legend', 'A':'label','B':'delta', 'C':'marker_color',
               'D':'size_units', 'E':'userpan', 'F':'scroll', 'G':'choices', 'H':'depth', 'I':'round'}
 
-// methods are X in {'m': '23X....'}
+// methods are X in {'m': '23X....'} available: u
 var methods = {'a':'select', 'b':'pos', 'c':'start', 'd':'stop', 'f':'clear', // unused eghijklmnopvxyzCDFAB
 			   'q':'plot', 's':'add_to_trail',
-               't':'follow', 'u':'_attach_arrow', 'w':'clear_trail',
+               't':'follow', 'w':'clear_trail',
                'G':'bind', 'H':'unbind', 'I':'waitfor', 'J':'pause', 'K':'pick', 'L':'GSprint',
 		       'M':'delete', 'N':'capture'}
 
-var vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', '_attach_arrow',
+var vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', 
                 'direction', 'linecolor', 'bumpaxis', 'dot_color', 'ambient', 'add_to_trail', 'textcolor',
                 'foreground', 'background', 'ray', 'ambient', 'center', 'forward', 'normal',
                 'marker_color']
@@ -613,23 +613,16 @@ function o2vec3(p) {
 }
 
 function handler(data) {
+    "use strict";
     "use strict";
 
-    /*
-    // Debugging what is sent from server:
-    let found = false
-    for (let d in data) {
-        for (const i in data[d]) {
-            if (!found) {
-                found = true
-                console.log('================')
-            }
-            if (found) {
-                console.log(i, JSON.stringify(data[d][i]))
-            }
-        }
-    }
-    */
+	/*
+	console.log('---------------')
+	for (var d in data) {
+		for (var i in data[d]) console.log(i, JSON.stringify(data[d][i]))
+	}
+	*/
+
 
 	if (data.cmds !== undefined && data.cmds.length > 0) handle_cmds(data.cmds)
 	if (data.methods !== undefined && data.methods.length > 0) handle_methods(data.methods)
@@ -838,19 +831,6 @@ function handle_cmds(dcmds) {
 					// Display frames per second and render time:
 					//$("<div id='fps'/>").appendTo(glowObjs[idx].title)
 			}
-			case 'attach_arrow':  {
-                var attrs = ['pos', 'size', 'axis', 'up', 'color']
-				var o = glowObjs[cfg['obj']]
-				delete cfg['obj']
-				var attr = cfg['attr']
-				delete cfg['attr']
-                var val = cfg['attrval']
-                delete cfg['attrval']
-                if (attrs.indexOf(attr) < 0) attr = '_attach_arrow'
-                o.attr = val
-				glowObjs[idx] = attach_arrow( o, attr, cfg )
-				break
-			}
 			case 'attach_trail': {
 				if ( typeof cfg['_obj'] === 'string' ) {
 					var o = cfg['_obj'] // the string '_func'
@@ -939,8 +919,6 @@ async function handle_methods(dmeth) {
 			glowObjs[idx]['pos'] = val
 		} else if (method === 'add_to_trail') {
 			obj['_func'] = val
-		} else if (method === '_attach_arrow') {
-            obj.obj._attach_arrow = val
 		} else if (method === 'bind') {
 			var evts = val.split(' ')
 			for (var evt in evts) {
@@ -999,7 +977,6 @@ function handle_attrs(dattrs) {
 		var attr = cmd['attr']
 		var val = cmd['val']
 		var triangle_quad = ['v0', 'v1', 'v2', 'v3']
-		// vector attrs in attach_arrow have arbitrary names, so check for length 3 array instead
 		if (val instanceof vec) {
 			if (attr === 'pos' && (obj instanceof points || obj instanceof curve)) {
 				var ptlist = []

vpython/vpython.py

@@ -101,13 +101,13 @@
 
 # methods are X in {'m': '23X....'}
 # pos is normally updated as an attribute, but for interval-based trails, it is updated (multiply) as a method
-__methods = {'select':'a', 'pos':'b', 'start':'c', 'stop':'d', 'clear':'f', # unused eghijklmnopvxyzCDFAB
+__methods = {'select':'a', 'pos':'b', 'start':'c', 'stop':'d', 'clear':'f', # unused eghijklmnopvxyzCDFABu
              'plot':'q', 'add_to_trail':'s',
-             'follow':'t', '_attach_arrow':'u', 'clear_trail':'w',
+             'follow':'t', 'clear_trail':'w',
              'bind':'G', 'unbind':'H', 'waitfor':'I', 'pause':'J', 'pick':'K', 'GSprint':'L',
              'delete':'M', 'capture':'N'}
 
-__vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', '_attach_arrow',
+__vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', 
             'direction', 'linecolor', 'bumpaxis', 'dot_color', 'ambient', 'add_to_trail',
             'foreground', 'background', 'ray', 'ambient', 'center', 'forward', 'normal',
             'marker_color']
@@ -209,14 +209,18 @@ def empty(cls):
     def handle_attach(cls): # called when about to send data to the browser
         ## update every attach_arrow if relevant vector has changed
         for aa in cls.attach_arrows:
-            obj = baseObj.object_registry[aa._obj]
+            if not aa._run: continue
+            obj = baseObj.object_registry[aa._object]
+            if not hasattr(obj, aa.attr): # no longer an attribute of the object
+                continue
             vval = getattr(obj, aa.attr) # could be 'velocity', for example
             if not isinstance(vval, vector):
-                raise AttributeError("attach_arrow value must be a vector.")
-            if (isinstance(aa._last_val, vector) and aa._last_val.equals(vval)):
-                continue
-            aa.addmethod('_attach_arrow', vval.value)
-            aa._last_val = vector(vval) # keep copy of last vector
+                raise AttributeError('attach_arrow attribute "'+aa.attr+'" value must be a vector.')
+            if aa._last_pos.equals(obj._pos) and aa._last_val.equals(vval): continue
+            aa._last_val = vector(vval)      # keep copies of last vectors
+            aa._last_pos = vector(obj._pos)
+            aa.pos = obj._pos
+            aa.axis = aa._scale*vval
 
         ## update every attach_trail that depends on a function
         for aa in cls.attach_trails:
@@ -545,10 +549,6 @@ class standardAttributes(baseObj):
                         [],
                         ['texture', 'bumpmap', 'visible', 'pickable'],
                         ['v0', 'v1', 'v2', 'v3'] ],
-                 'attach_arrow': [ [ 'color', 'attrval'],
-                        [],
-                        ['shaftwidth', 'round', 'scale', 'obj', 'attr'],
-                        [] ],
                  'attach_trail': [ ['color'],
                         [],
                         ['radius', 'pps', 'retain', 'type', '_obj'],
@@ -721,14 +721,14 @@ def setup(self, args):
 
     # attribute vectors have these methods which call self.addattr()
     # The vector class calls a change function when there's a change in x, y, or z.
-        noSize = ['points', 'label', 'vertex', 'triangle', 'quad', 'attach_arrow', 'attach_trail']
+        noSize = ['points', 'label', 'vertex', 'triangle', 'quad', 'attach_trail']
         if not (objName == 'extrusion'): # 
             self._color.on_change = self._on_color_change
         if objName not in noSize:
             self._axis.on_change = self._on_axis_change
             self._size.on_change = self._on_size_change
             self._up.on_change = self._on_up_change
-        noPos = ['curve', 'points', 'triangle', 'quad', 'attach_arrow']
+        noPos = ['curve', 'points', 'triangle', 'quad']
         if objName not in noPos:
             self._pos.on_change = self._on_pos_change
         elif objName == 'curve':
@@ -1330,24 +1330,6 @@ def headlength(self,value):
         if not self._constructing:
             self.addattr('headlength')
 
-class attach_arrow(standardAttributes):
-    def __init__(self, obj, attr, **args):
-        attrs = ['pos', 'size', 'axis', 'up', 'color']
-        args['_default_size'] = None
-        a = getattr(obj, attr) # This raises an error if obj does not have attr
-        if not isinstance(a, vector): raise AttributeError('The attach_arrow attribute "'+attr+ '" is not a vector.')        
-        self.obj = args['obj'] = obj.idx
-        self.attr = args['attr'] = attr # could be for example "velocity"
-        self.attrval = args['attrval'] = getattr(baseObj.object_registry[self.obj], attr)
-        args['_objName'] = "attach_arrow"
-        self._last_val = None
-        self._scale = 1
-        self._shaftwidth = 0
-        self._round = False
-        super(attach_arrow, self).setup(args)
-        # Only if the attribute is a user attribute do we need to add to attach_arrows:
-        if attr not in attrs: baseObj.attach_arrows.append(self)
-
     @property
     def round(self):
         return self._round
@@ -1374,10 +1356,34 @@ def shaftwidth(self, value):
             self.addattr("shaftwidth")
 
     def stop(self):
-        self.addmethod('stop', 'None')
+        self._run = self.visible = False
 
     def start(self):
-        self.addmethod('start', 'None')
+        self._run = self.visible = True
+    
+def attach_arrow(o, attr, **args): # factory function returns arrow with special attributes
+    '''
+    The object "o" with a vector attribute "p" will have an arrow attached with options such as "color".
+    The length of the arrow will be args.scale*o.p", updated with every render of the scene.
+    If one creates a new attachment with "arr = attach_arrow(obj, attr, options)" you
+    can later change (for example) its color with "arr.color = ..."
+    '''
+    if not hasattr(o, attr): raise AttributeError('Cannot attach an arrow to an object that has no "'+attr+'" attribute.')
+    if not isinstance(getattr(o, attr), vector): raise AttributeError('The attach_arrow attribute "'+attr+ '" is not a vector.')
+    if not isinstance(o.pos, vector): raise AttributeError("The object's pos attribute is not a vector.")
+    
+    scale = 1
+    if 'scale' in args: scale = args['scale']
+    shaftwidth = 0.5*o._size.y
+    if 'shaftwidth' in args: shaftwidth = args['shaftwidth']
+    c = o.color
+    if 'color' in args: c = args['color']
+    # Set _last_val to strange values so that the first update to WebGL won't match:
+    a = arrow(canvas=o.canvas, pickable=False, _object=o.idx, attr=attr, color=c,
+              scale=scale, shaftwidth=shaftwidth, _run=True,
+              _last_val=vector(134.472, 789.472, 465.472), _last_pos=vector(134.472, 789.472, 465.472))
+    baseObj.attach_arrows.append(a)
+    return a
 
 class attach_trail(standardAttributes):
     def __init__(self, obj, **args):
@@ -2428,15 +2434,15 @@ def foreground(self): return self._foreground
     @foreground.setter
     def foreground(self,val):
         if not isinstance(val, vector): raise TypeError('foreground must be a vector')
-        self._foreground = vector(value)
+        self._foreground = vector(val)
         self.addattr('foreground')
 
     @property
     def background(self): return self._background
     @background.setter
     def background(self,val):
         if not isinstance(val,vector): raise TypeError('background must be a vector')
-        self._background = vector(value)
+        self._background = vector(val)
         self.addattr('background')
 
     @property
@@ -3404,13 +3410,13 @@ def setup(self, args):
         ## default values of common attributes
         self._constructing = True
         argsToSend = []
-        objName = args['_objName']
+        self.objName = args['_objName']
         del args['_objName']
         if 'pos' in args:
             self.location = args['pos']
             if self.location == print_anchor:
                 #self.location = [-1, print_anchor]
-                raise AttributeError(objName+': Cannot specify "print_anchor" in VPython 7.')
+                raise AttributeError(self.objName+': Cannot specify "print_anchor" in VPython 7.')
             argsToSend.append('location')
             del args['pos']
         if 'canvas' in args:  ## specified in constructor
@@ -3438,12 +3444,12 @@ def setup(self, args):
 
         ## override default scalar attributes
         for a,val in args.items():
-            if a in controls.attrlists[objName]:
+            if a in controls.attrlists[self.objName]:
                 argsToSend.append(a)
                 setattr(self, '_'+a, val)
             else:
                 setattr(self, a, val)
-        cmd = {"cmd": objName, "idx": self.idx}
+        cmd = {"cmd": self.objName, "idx": self.idx}
         cmd["canvas"] = self.canvas.idx
 
         ## send only args specified in constructor
@@ -3465,10 +3471,10 @@ def bind(self, value):
 
     @property
     def pos(self):
-        raise AttributeError(objName+' pos attribute is not available.')
+        raise AttributeError(self.objName+' pos attribute is not available.')
     @pos.setter
     def pos(self, value):
-        raise AttributeError(objName+' pos attribute cannot be changed.')
+        raise AttributeError(self.objName+' pos attribute cannot be changed.')
 
     @property
     def disabled(self):

vpython/vpython_libraries/glow.min.js

@@ -397,14 +397,14 @@
               'y':'markers', 'z':'legend', 'A':'label','B':'delta', 'C':'marker_color',
               'D':'size_units', 'E':'userpan', 'F':'scroll', 'G':'choices', 'H':'depth', 'I':'round'}
 
-// methods are X in {'m': '23X....'}
+// methods are X in {'m': '23X....'} available: u
 var methods = {'a':'select', 'b':'pos', 'c':'start', 'd':'stop', 'f':'clear', // unused eghijklmnopvxyzCDFAB
 			   'q':'plot', 's':'add_to_trail',
-               't':'follow', 'u':'_attach_arrow', 'w':'clear_trail',
+               't':'follow', 'w':'clear_trail',
                'G':'bind', 'H':'unbind', 'I':'waitfor', 'J':'pause', 'K':'pick', 'L':'GSprint',
 		       'M':'delete', 'N':'capture'}
 
-var vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', '_attach_arrow',
+var vecattrs = ['pos', 'up', 'color', 'trail_color', 'axis', 'size', 'origin', 
                 'direction', 'linecolor', 'bumpaxis', 'dot_color', 'ambient', 'add_to_trail', 'textcolor',
                 'foreground', 'background', 'ray', 'ambient', 'center', 'forward', 'normal',
                 'marker_color']
@@ -539,7 +539,7 @@
 		for (var i in data[d]) console.log(i, JSON.stringify(data[d][i]))
 	}
 	*/
-	
+
 
 	if (data.cmds !== undefined && data.cmds.length > 0) handle_cmds(data.cmds)
 	if (data.methods !== undefined && data.methods.length > 0) handle_methods(data.methods)
@@ -748,19 +748,6 @@
 					// Display frames per second and render time:
 					//$("<div id='fps'/>").appendTo(glowObjs[idx].title)
 			}
-			case 'attach_arrow':  {
-                var attrs = ['pos', 'size', 'axis', 'up', 'color']
-				var o = glowObjs[cfg['obj']]
-				delete cfg['obj']
-				var attr = cfg['attr']
-				delete cfg['attr']
-                var val = cfg['attrval']
-                delete cfg['attrval']
-                if (attrs.indexOf(attr) < 0) attr = '_attach_arrow'
-                o.attr = val
-				glowObjs[idx] = attach_arrow( o, attr, cfg )
-				break
-			}
 			case 'attach_trail': {
 				if ( typeof cfg['_obj'] === 'string' ) {
 					var o = cfg['_obj'] // the string '_func'
@@ -816,7 +803,6 @@
 				cfg.objName = obj
 				cfg.bind = control_handler
 				cfg = fix_location(cfg)
-				console.log('menu cfg', cfg)
 				glowObjs[idx] = menu(cfg)
 				if (cfg['selected'] === 'None') {
 					cfg['selected'] = null                              
@@ -850,8 +836,6 @@
 			glowObjs[idx]['pos'] = val
 		} else if (method === 'add_to_trail') {
 			obj['_func'] = val
-		} else if (method === '_attach_arrow') {
-            obj.obj._attach_arrow = val
 		} else if (method === 'bind') {
 			var evts = val.split(' ')
 			for (var evt in evts) {
@@ -909,9 +893,7 @@
 		var obj = glowObjs[idx]
 		var attr = cmd['attr']
 		var val = cmd['val']
-		console.log(obj, attr, val)
 		var triangle_quad = ['v0', 'v1', 'v2', 'v3']
-		// vector attrs in attach_arrow have arbitrary names, so check for length 3 array instead
 		if (val instanceof vec) {
 			if (attr === 'pos' && (obj instanceof points || obj instanceof curve)) {
 				var ptlist = []